Mechanics of solid tissue invasion by the mammalian pathogen Pythium insidiosum.


The relative significance of mechanical penetration versus the action of substrate-degrading enzymes during solid tissue invasion has not been established for any fungal disease. Pythium insidiosum is an oomycete fungus (or stramenopile) that causes a rare, but potentially lethal infection in humans and other mammalian hosts. Experiments with miniature strain gauges showed that single hyphal apices of this pathogen exert forces of up to 6.9 microN, corresponding to maximum pressures of 0.3 microN microm(-2) or MPa. Samples of cutaneous and subcutaneous tissue from fresh human cadavers displayed a mean strength (resistance to needle puncture) of 24 microN microm(-2), and a mean pressure of 30 microN microm(-2) was necessary to penetrate skin strips from slaughtered horses. These experiments demonstrate that P. insidiosum does not exert sufficient pressure to penetrate undamaged skin by mechanics alone, but must effect a decisive reduction in tissue strength by proteinase secretion.

Cite this paper

@article{Ravishankar2001MechanicsOS, title={Mechanics of solid tissue invasion by the mammalian pathogen Pythium insidiosum.}, author={Jagadesa P Ravishankar and Christopher S. Davis and Diana J. Davis and Erin L. MacDonald and Stephanie Makselan and Laurie M. Millward and Nicholas P . Money}, journal={Fungal genetics and biology : FG & B}, year={2001}, volume={34 3}, pages={167-75} }